Many people experience natural tooth loss due to disease or injury. Consequently, various techniques have been developed to replace lost teeth. In some cases there are sufficient teeth remaining adjacent the opening where a prosthetic tooth is to be placed, in these cases a bridge may be used. If however, insufficient natural teeth remain to support and stabilize the bridge, a denture may be prepared and seated against the patient's gingiva. In yet other instances, a dental surgeon may use a dental implant.
When a dental implant is to be used, a hole is first drilled into a patient's jawbone (mandibular or maxillary bone), the implant is then attached by either screwing it or tapping it into the opening. After the implant is inserted into the jawbone, the opening in the gingiva is surgically closed and allowed to heal. The healing time is generally up to six months during which time the bone and gingiva will regenerate around the implant to secure it. After sufficient healing time, a second procedure takes place wherein the submerged implant is located and the gingiva is reopened. The dental surgeon attaches an abutment cap to the implant body and another healing period begins.
After the second healing period, the dental surgeon removes the abutment cap and selects an abutment for insertion into the implant body. The prosthetic tooth is positioned on the abutment. In order for the tooth to be properly positioned, the direction of projection of the abutment is often critical. When a number of teeth are to be positioned adjacent one another, it is required that adjacent abutments be substantially parallel. In most cases, when multiple or even single implants are inserted, however, parallelism cannot be achieved. Thus, final installation is almost always achieved by modifying the shape of the abutment head.
Abutments are formed with heads having various angles and lengths so they can properly seat a prosthetic tooth in a patient's mouth. A dental surgeon must estimate and decide which abutment is appropriate for a given situation. This “trial and error” approach creates more work for the dental surgeon by having the dental surgeon repeatedly insert and remove abutments until a proper fit is found. Also, intra-oral connection of components is difficult due to the close tolerances to which the components are made. In addition, the tightening of abutments onto the implant body is difficult due to the shape of the abutment. Also, screws loosen and screws and abutment heads can be swallowed. Furthermore, the abutments may need to be ground to allow the prosthetic tooth to fit properly. Most abutments are made from titanium and, therefore, are more difficult to work with than natural teeth. These procedures are time-consuming and in many cases effect the retention of the prosthetic tooth. Also, in many cases, the final restoration does not fit accurately because the implant has ankylosed with the bone and cannot move.
With the present invention, after the prosthetic appliance is assembled, if there is a tolerance or insertion problem, adjustments may be made.